Valve grinder



Jan. 10, 1928. 1,655,821

G. R. RICH VALVE GRINDER File Fe'b. 16, 1927 2- 'j' Patented Jan. 10,1928.

UNITED STATES GEORGE B. RICH, OFBATTLE CREEK, MICHIGAN.

VALVE GBINDEB.

Application led February 16, 1987. Serial No. 168,531.

This invention relates to valve grinders' and more particularly to theclutch thereof which holds the poppet valve during the process ofgrinding 'its tapered seating face. Tapered face poppet valves ofinternal combustion engines seat upon correspondingly tapered valveseats formed in the cylinder blocks of the engines and unless the valvesseat perfectly, leaks occur bet-Ween the valves and their seats, therebycausing poor compression with a corresponding loss of power. A poppetvalve of this kind is provided with a stem and a disc like head, whichis formed with a vtapered seating face as is well understood. In manycases it is preferred to grind the valve stem on a centerless grindf er,because of the great accuracy which is obtained in the method ofgrinding valve stems with a centerless grinder. The difficulty inholding a valve during the process of grinding .its 'tapered seatingface is that of preventing the valve from rotating out of its true axis,and from wabbling or chattering. When held in the ordinary chuck of avalve grinding fixture, the valve is apt to be held ofi center becauseof the wear on the jaws of the collet and because the stem is sometimesnot ground true`- One of the 'objects of my invention is to provide achuck of novel form for holding the valve stem rigidlyagainst anyvibration and for rotating it upon its true axis whereby the taperedseating face thereof may be accurately ground into a true circle. Withthese ends in view this invention relates to a valve grinderihaving achuck providedwith a collet for gripping the end of the valve stem and avalve centering collar or collet in which the valve stem is accuratelycentered and held by a ti ht iit, whereby when the valve is rotated ythe chuckit is caused to rotate'on its true center and its taperedseating face may therefore be ground accurately and true. The inventionfurther consists in the several novel features herein` after fully setforth and ciaimed.

The invention is clearly illustrated in the accompanying drawing, inwhich:

Fig. 1 is a plan of a valve grinder embodying a simple form of thepresent invention, and showing a valve heid in grinding positiontherein, certain parts of the fgrindini7 member being broken away; Fig.2 is tical, longitudinai section taken on 2-2 of Fig. upon a siightiyenier,- ig. 3 is a deta'd sectionai view, in

of the end of the chuck, which contains the st em gripping collar andFig. 4 is an end view oo ing in the direction of the arrow 4 in Fig. 3with the valve removed.

Referring to said drawing, the reference character 5 designates thegrinding member ofthe machine, which member embodies a grlnding wheel 6mounted Ona shaft 7, which is journaled in bearings, one of which isseen at 8, and having a belt pulley 9 mounted thereon, belted to asuitable drive pulley, by means of which the grinding wheel may berotated. These parts comprise the grinding tool of the grinding member,and as usual it is capable of being moved 1n lines parallel with theaxis of the shaft and in lmes at right angles thereto whereby therinding wheel may be fed to and across t e taperedf seating face of thevalve A, which is to be ground.

Mounted adjacent to the grinding member is a chuck fixture 10, having abase portion 11 upon which is mounted a head 12. The head is boredlongitudinall and the axis of the bore is set at a suitab e an le withrespect to the grinding face of t e grinding Wheel 6, an angle of 45degrees belng here shown, inasmuch as that angle is one of the standardangles of tapered seating faces of poppet valves for internal combustionengines.

Secured in the bore of the head 12 is a bearing bushin 13, in which isrotatively mounted the hollow spindle 14 of the chuck. uo A belt pulley15 is mounted on the hollow spindle 14.- and is belted to a suitabledrive pulley and furnishes the means for rotating` the hollow spindle14. A. flange 16 on the hollow spindle 14 bears against one end of esthe bushing 13, and a collar 17 mounted upon said hollow spindle bearsagainst the other end of said bushing. Nuts 18 threaded upon the outerend of the hollow spindle and bearing against the collar 17, are loeprovided for securing the hollow spindie against endafise movement inthe bushin in the hollow of the hoilovv spindle A is xediy secured asieeve 19, which has an interiorly-tapered front end that engages withion the tapered outer side of the 52,@ of a stem gripping ceiiet 2i.coiiet is adapted to grip the stem e, of the valve A, 'niiet ground.rEhe coilet 2i c i $55,

H i L wise direction by lingers 23 mounted upon a support 2A, which isthreadedly secured upon the outer end of the tubular member 22. A.finger actuatinfr collar 2G is slidably mounted on' the hollow spindle14: and has a tapered end, which engages with the lingers 23 and saidcollar is arranged to spread the ends ot said lingers apart when forcedtowards said tin ers to thereby cause said lingers to move t e tubularmember 22 in an endvvise outward direction to thereby clamp the jaws ofthe collet 21 upon the valve stein a. A hand lever 27 fulcrunied upon anarm 28 of-the base 11 and provided with a fork, having pins arranged toengage in a circumferential groove in-the collar 26 provides means forshitting the collar 26 and thus operating the collet 21.

rthe collet 21 is located at a considerable distance away from the outerend ot' the hollow spindle 14C instead of being located at its outer endand isarranged to `grip the valve stem at a place distantly removed fromthe valve head al, and means are pro- `vided at the extreme outer end otthe hollow spindle 14: for centering and gripping the valve stein at aplace adJacent the valve head ai. and said means will now be delscribed.

Fixedly secured in the outer end of the hollow spindle 1li is a bushing30, which contains a central bore 31 through which the valve stem may beinserted into the collet 21. Said bushing is provided with an externallythreaded lange 32 on which is screwed a nut 33 that may be screwedagainst the outer Ytace ot one ot the clamp nuts 18 to Withdraw thebushing 30 :from the hollow spindle la. rlhe outer end of the bushing 30is bored out to torni a cavity 34: in Which is secured a valve centeringcollar or collet 35, Whichhis termed with faws 36 and the jaw portion ofthe collar 35 is accurately bored to tit the stein (t9 ot the poppetvalve. A nut 37 is threadedly secured upon the externally threaded end38 ot the bushing' 30 and said nut is formed with a tapered inner face39 'which fits the tapered outer tacos ot the javvs 3@ of the collar 35.Set screws i0 threadedly secured in the nut 37 are arranged to bearagainst the outer 'faces ci: the collar jaws 3S and provide meanswhereupon any or all ot said may be adjusted toward or away from theaxis oi rotation of the chucl-. Vfhen poppet valves are Lcfrtrund on acenterless stein grinder a very slight taper or 'daring part Lil isground upon the end et the valve stem adjacent the head.

ot the tion is Wl en ohneA e. d

valve., which tapered ordering porconcentric the asis of the valve.valve is inserted into oecoines tightlv wedged into the *r collar orcollet stern is gripped by the collet 21 and the chuck is rotated thevalve will therefore be rotated upon the true axis ot the valve stem andany wabbling or chattering thereof is eliminated. lt' desired the collaror collet 35 may be omitted and the bore 3l may extend to the front endot the bushing 30. ln this case the flaring ground end of the valve stemWedges directly in the bore ot' the bushing.

inasmuch as the valve stem sometimes becomes tightly wedged in thecollar or the collet, means have been provided for freeing thevalve stemfrom the collets. A simple torni of means has been shown in the drawingand comprises a stem 42 contained in the tubular member 22 and having areduced end portion t3 of the same diameter or a diameter slightly lessthan that of the valve stein and arranged to he struck against thesaine. rl`he other end of the stern ll2 projects beyond ythe rear endoit' the hollow spindle 14 and is secured to a yoke member elli, as torinstance by nuts i5 threaded on the threaded end ot the stein l2 andgrippino' the yoke member between them. Said yo e lll is connected Wit-hthe forks of the hand lever 27 by nuts 47. An adjustable collar i6 isthreadedly secured upon the outer end et the stern 42 and is adapted tobe forcibly brought into contact with the rear end el the tubular member22 to thereby jar the collet 21 tree in case it may become wedgedtightly on the valve stein.

lrthe operation et this device, the stem ot the valve to be ground isinserted through the collar 35 and into the collet 21 and the hand lever2'? thereupon moved in the direction to clamp the collet 2l upon thevalve stein. ln inserting the valve stein into the chuck the attendanttorcibly presses the tapered or daring end el ot' the valve stern into avvedging contact with the collar or collet 35 so as to rnalre a tight htbetween the two. lt Will be understood that both the grinding Wheelandthe chuck are in constant rotation. The attendant then moves thegrinding Wheel up to the rough beveled seating tace ol the valve headand accomplishes the= grinding operation in the usual grinding awaysuficien't material to produce a smooth surface. When linished, thetendant moves the hand lever 2'? hack thereby releasing; the collet 2lfrom the valve stein and in doing; so the yoke del is draivn lorivardsu'ilieiently to the forward end of the reduced portion d3 ot the valveejectsteni. l2 into engagement with the end of he valve and therebyreleasing it :troni ts wedged condition with the collet or col- -2 me.f7.1.;

f1 ceive the flaring act form of the construction shown and described,but intend, in the following claims, to point out all of the inventiondisclosed herein,

I claim as new, ters Patent:

l. In a valve grinder for grinding the tapered seating face ofpoppetvalves, a rotary valve stem holding chuc t, having an endwisemovable collet therein, arranged to grip one end of the valve stem,collet actuating mcans, and a stein centering collar stationarilysecured in thel outer end of the chuck, said collar having a cylindricalbore adapted to rehead end of a valve stem and the collet being movablein a direction to wedge the flaring head end of the valve in thecylindrical bore of the collar, whereby the two `ends of the valve stemare tightly held in `centered position in the collar and collet.

2. In a. valve grinder for grinding the tapered seating face of poppetvalves. a rotary,

and desire to secure by Letvalve stem holding chuck, having chuck clos.

ing means, a stem gripping collet in said chuck, a collar stationarilysecured at the end of the chuck, said collar being formed with radiallyadjustable endwise engageable centering jaws, and means for radiallyadjusting the jaws of the collar independently of the chuck closingmeans.

3. In a valve grinder for grinding the tapered seating face of poppetvalves, the combination of a rotary, valve stem holding chuck, having astem gripping collet therein, collet actuating means, a stem centeringmember at the end of the'clluck and having a cylindrical bore into whichthe flaring head end of the valve stemv is moved into a tight y fit bysaid collet and its actuating means, a

valve ejecting spindle, a single hand lever and operative connectionsbetween said hand lever and the collet actuating means and between saidhand lever and the valve ejecting spindle whereby the collet actuatingmeans and valve ejecting spindle are actuated simultaneously.

GEORGE R. RICH.

